Recent Research Highlights

Coupling of ALPs with photons may lead to photons escaping optically opaque regions by oscillating into ALPs. This phenomenon may be viewed as the Light Shining through Wall (LSW) scenario in an astrophysical setting, and can be employed for appropriately chosen obscured magnetars.  

 Light Shining Through Wall Bounds on Axions From Obscured Magnetars 

Ultralight scalar fields produced from their interactions with the intense EM fields near a compact star can have observable consequences such as change of photon dispersion relations and the spin-down rate of a binary system.   

Constraining electromagnetic couplings of ultralight scalars from compact stars 

• Analytical expressions for the conversion probability of muon neutrino to electron neutrino were calculated in the presence of sterile neutrinos, with exact dependence on the sterile mass squared difference and matter effects. Experiments like DUNE have the ability to identify sterile mass ordering. 

Sterile neutrinos: propagation in matter and sensitivity to sterile mass ordering 

• The effects of Lorentz violation and non-standard interactions of neutrinos can mimic each other in neutrino oscillations at long-baseline experiments. But observations of core-passing atmospheric neutrinos and antineutrinos can break this degeneracy. 

Discriminating between Lorentz violation and non-standard interactions using core-passing atmospheric neutrinos at INO-ICAL 

• A new perturbative technique was developed for analyzing physical situations where the effective Hamiltonian has non-commuting Hermitian and anti-Hermitian components, a situation that arises when neutrinos pass through matter.  

Analytic treatment of 3-flavor neutrino oscillation and decay in matter  

Neutrino Propagation When Mass Eigenstates and Decay Eigenstates Mismatch